US 9,790,363 B2 · Assignee: SABIC GLOBAL TECHNOLOGIES B.V. · Inventors: Chen; Lin et al.
Claude can sketch it from the patent text.
A composition includes specific amounts of an aromatic polycarbonate, a block polycarbonate-polysiloxane, a poly(alkylene terephthalate), a block polyestercarbonate, and an organophosphate ester. Relative to a corresponding composition lacking the block polyestercarbonate, the composition exhibits improved solvent resistance while substantially maintaining impact strength, melt flow, and flame retardancy. The composition is useful for fabricating articles that may come into contact with liquid chemicals or chemical vapors.
Polycarbonate is an engineering plastic widely used in various applications due to its good heat resistance, impact resistance, and transparency. Polycarbonate's ability to self-char during combustion makes it especially suitable for uses in which flame retardancy is needed, for example in housing parts for electrical and electronic devices. However, in applications in which it comes into direct contact with chemicals, such as in office equipment and kitchen equipment, polycarbonate-based materials can exhibit environmental stress cracking (ESC) due to their relatively poor chemical resistance. Incorporating thermoplastic polyesters into the polycarbonate compositions has been demonstrated to improve chemical resistance. See, e.g., European Patent No. 0 992 542 B1 to Matsumoto, and U.S. Pat. No. 6,590,015 B1 to Eckel et al. However, flame retardancy and impact strength are both compromis
Ask Claude for concept sketches based only on the patent's text. They are not part of the patent.
What the patent claimed, word for word. All of it is now free to use.
This application is a National Stage application of PCT/IB2015/051082, filed 02/13/2015, which claims the benefit of U.S. Nonprovisional Application Ser. No. 14/191,488, filed 02/27/2014(currently abandoned), both of which are incorporated by reference in their entirety herein.
Polycarbonate is an engineering plastic widely used in various applications due to its good heat resistance, impact resistance, and transparency. Polycarbonate's ability to self-char during combustion makes it especially suitable for uses in which flame retardancy is needed, for example in housing parts for electrical and electronic devices. However, in applications in which it comes into direct contact with chemicals, such as in office equipment and kitchen equipment, polycarbonate-based materials can exhibit environmental stress cracking (ESC) due to their relatively poor chemical resistance.
Incorporating thermoplastic polyesters into the polycarbonate compositions has been demonstrated to improve chemical resistance. See, e.g., European Patent No. 0 992 542 B1 to Matsumoto, and U.S. Pat. No. 6,590,015 B1 to Eckel et al. However, flame retardancy and impact strength are both compromised by the addition of thermoplastic polyester. And attempts to compensate for reduced flame retardancy by the addition of organophosphate esters yield undesirable decreases in heat resistance and impact strength. International Patent Application Publication No. WO 2012/058821 A1 of Wan et al. describes a polycarbonate-polyester molding composition incorporating an “organopolysiloxane-polycarbonate block copolymer”. That composition exhibits a desirable balance of mechanical properties, flame retardancy, and melt flow. But the composition's chemical resistance is inadequate for some applications with chemical exposure. There remains a need for polycarbonate-polyester blends exhibiting improved chemical resistance while substantially maintaining impact strength, melt flow, heat resistance, and flame retardancy.
One embodiment is a composition comprising, based on the total weight of the composition, 5 to 50 weight percent of an aromatic polycarbonate; 10 to 40 weight percent of a block polycarbonate-polysiloxane; 5 to 35 weight percent of a poly(alkylene terephthalate); 5 to 50 weight percent of a block polyestercarbonate comprising a polyester block comprising resorcinol ester repeat units having the structure
##STR00001## and a polycarbonate block comprising carbonate repeat units having the structure
##STR00002## wherein at least 60 percent of the total number of R.sup.1 groups are aromatic; and 4 to 20 weight percent of an organophosphate ester.
Another embodiment is an article comprising the composition.
These and other embodiments are described in detail below.
The present inventors have determined that improved chemical resistance is exhibited by a composition that includes specific amounts of an aromatic polycarbonate, a block polycarbonate-polysiloxane, a poly(alkylene terephthalate), a block polyestercarbonate, and an organophosphate ester. The improved chemical resistance is achieved while substantially maintaining impact strength, melt flow, heat resistance, and flame retardancy. Thus, one embodiment is a composition comprising, based on the total weight of the composition, 5 to 50 weight percent of an aromatic polycarbonate; 10 to 40 weight percent of a block polycarbonate-polysiloxane; 5 to 35 weight percent of a poly(alkylene terephthalate); 5 to 50 weight percent of a block polyestercarbonate comprising a polyester block comprising resorcinol ester repeat units having the structure
##STR00003## and a polycarbonate block comprising carbonate repeat units having the structure
##STR00004## wherein at least 60 percent of the total number of R.sup.1 groups are aromatic; and 4 to 20 weight percent of an organophosphate ester.
The composition includes an aromatic polycarbonate. “Polycarbonate” as used herein means a polymer or copolymer having repeating structural carbonate units of the formula
##STR00005## wherein at least 60 percent of the total number of R.sup.1 groups are aromatic. Specifically, each R.sup.1 can be derived from a dihydroxy compound such as an aromatic dihydroxy compound of the formula
##STR00006## wherein n, p, and q are each independently 0, 1, 2, 3, or 4; R.sup.a is independently at each occurrence halogen, or unsubstituted or substituted C.sub.1-10 hydrocarbyl; and X.sup.a is a single bond, —O—, —S—, —S(O)—, —S(O).sub.2—, —C(O)—, or a C.sub.1-18 hydrocarbylene, which can be cyclic or acyclic, aromatic or non-aromatic, and can further comprise one or more heteroatoms selected from halogens, oxygen, nitrogen, sulfur, silicon, or phosphorous. As used herein, the term “hydrocarbyl”, whether used by itself, or as a prefix, suffix, or fragment of another term, refers to a residue that contains only carbon and hydrogen unless it is specifically identified as “substituted hydrocarbyl”. The hydrocarbyl residue can be aliphatic or aromatic, straight-chain, cyclic, bicyclic, branched, saturated, or unsaturated. It can also contain combinations of aliphatic, aromatic, straight chain, cyclic, bicyclic, branched, saturated, and unsaturated hydrocarbon moieties. As used herein, “substituted” means including at least one substituent such as a halogen (i.e., F, Cl, Br, I), hydroxyl, amino, thiol, carboxyl, carboxylate, amide, nitrile, sulfide, disulfide, nitro, C.sub.1-18 alkyl, C.sub.1-18 alkoxyl, C.sub.6-18 aryl, C.sub.6-18 aryloxyl, C.sub.7-18 alkylaryl, or C.sub.7-18 alkylaryloxyl. So, when the hydrocarbyl residue is described as substituted, it can contain heteroatoms in addition to carbon and hydrogen.
Some illustrative examples of specific dihydroxy compounds include the following: bisphenol compounds such as 4,4′-dihydroxybiphenyl, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)diphenylmethane, bis(4-hydroxyphenyl)-1-naphthylmethane, 1,2-bis(4-hydroxyphenyl)ethane,1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2-(4-hydroxyphenyl)-2-(3-hydroxyphenyl)propane, bis(4-hydroxyphenyl)phenylmethane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 1,1-bis (hydroxyphenyl)cyclopentane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)isobutene, 1,1-bis(4-hydroxyphenyl)cyclododecane, trans-2,3-bis(4-hydroxyphenyl)-2-butene, 2,2-bis(4-hydroxyphenyl)adamantane, alpha,alpha'-bis(4-hydroxyphenyl)toluene, bis(4-hydroxyphenyl)acetonitrile, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 2,2-bis(3-ethyl-4-hydroxyphenyl)propane, 2,2-bis(3-n-propyl-4-hydroxyphenyl)propane, 2,2-bis(3-isopropyl-4-hydroxyphenyl)propane, 2,2-bis(3-sec-butyl-4-hydroxyphenyl)propane, 2,2-bis(3-t-butyl-4-hydroxyphenyl)propane, 2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane, 2,2-bis(3-allyl-4-hydroxyphenyl)propane, 2,2-bis(3-methoxy-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 1,1-dichloro-2,2-bis(4-hydroxyphenyl)ethylene, 1,1-dibromo-2,2-bis(4-hydroxyphenyl)ethylene, 1,1-dichloro-2,2-bis(5-phenoxy-4-hydroxyphenyl)ethylene, 4,4′-dihydroxybenzophenone, 3,3-bis(4-hydroxyphenyl)-2-butanone, 1,6-bis(4-hydroxyphenyl)-1,6-hexanedione, ethylene glycol bis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)sulfoxide, bis(4-hydroxyphenyl)sulfone, 9,9-bis(4-hydroxyphenyl)fluorine, 2,7-dihydroxypyrene, 6,6′-dihydroxy-3,3,3′,3′-tetramethylspiro(bis)indane (“spirobiindane bisphenol”), 3,3-bis(4-hydroxyphenyl)phthalimide, 2,6-dihydroxydibenzo-p-dioxin, 2,6-dihydroxythianthrene, 2,7-dihydroxyphenoxathin, 2,7-dihydroxy-9,10-dimethylphenazine, 3,6-dihydroxydibenzofuran, 3,6-dihydroxydibenzothiophene, and 2,7-dihydroxycarbazole; resorcinol, substituted resorcinol compounds such as 5-methyl resorcinol, 5-ethyl resorcinol, 5-propyl resorcinol, 5-butyl resorcinol, 5-t-butyl resorcinol, 5-phenyl resorcinol, 5-cumyl resorcinol, 2,4,5,6-tetrafluoro resorcinol, 2,4,5,6-tetrabromo resorcinol, or the like; catechol; hydroquinone; substituted hydroquinones such as 2-methyl hydroquinone, 2-ethyl hydroquinone, 2-propyl hydroquinone, 2-butyl hydroquinone, 2-t-butyl hydroquinone, 2-phenyl hydroquinone, 2-cumyl hydroquinone, 2,3,5,6-tetramethyl hydroquinone, 2,3,5,6-tetra-t-butyl hydroquinone, 2,3,5,6-tetrafluoro hydroquinone, and 2,3,5,6-tetrabromo hydroquinone.
Specific dihydroxy compounds include resorcinol, 2,2-bis(4-hydroxyphenyl) propane (“bisphenol A” or “BPA”), 3,3-bis(4-hydroxyphenyl) phthalimidine, 2-phenyl-3,3′-bis(4-hydroxyphenyl) phthalimidine (also known as N-phenyl phenolphthalein bisphenol, “PPPBP”, or 3,3-bis(4-hydroxyphenyl)-2-phenylisoindolin-l-one), 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane (DMBPC), 1,1-bis(4-hydroxy-3-methylphenyl)-3,3,5-trimethylcyclohexane (isophorone bisphenol), and combinations thereof.
In some embodiments, at least 90 percent of the total number of R.sup.1 groups in the polycarbonate have the formula
##STR00007## In some embodiments, the polycarbonate comprises or consists of bisphenol A polycarbonate resin.
More than one polycarbonate can be used. For example, the composition can comprise a first polycarbonate having a weight average molecular weight of 18,000 to 25,000 atomic mass units and a second polycarbonate having a weight average molecular weight of 27,000 to 35,000 atomic mass units.
Methods of forming polycarbonates are known, and many are commercially available from suppliers including SABIC Innovative Plastics, Bayer MaterialScience, and Mitsubishi Chemical Corp.
The composition comprises the polycarbonate in an amount of 5 to 50 weight percent, based on the total weight of the composition. Within this range, the polycarbonate amount can be 10 to 40 weight percent, specifically 15 to 36 weight percent.
In addition to the aromatic polycarbonate, the composition comprises a block polycarbonate-polysiloxane. A block polycarbonate-polysiloxane is a polycarbonate copolymer comprising at least one polycarbonate block and at least one polysiloxane block. In some embodiments, the block polycarbonate-polysiloxane comprises multiple polycarbonate blocks and multiple polysiloxane blocks. The block polycarbonate-polysiloxane can be transparent, translucent, or opaque, depending on its composition.
Block polycarbonate-polysiloxanes and methods for their preparation are known and described, for example, in U.S. Pat. Nos. 3,419,634 and 3,419,635 to Vaughn, U.S. Pat. No. 3,821,325 to Merritt et al., U.S. Pat. No. 3,832,419 to Merritt, and U.S. Pat. No. 6,072,011 to Hoover. Block polycarbonate-polysiloxanes are also commercially available as LEXAN™ EXL resins from SABIC Innovative Plastics.
In some embodiments, each of the at least one polysiloxane blocks of the copolymer comprises diorganosiloxane units of the formula
##STR00008## wherein each occurrence of R.sup.2 is independently C.sub.1-13 hydrocarbyl. Examples of suitable hydrocarbyl groups include C.sub.1-C.sub.13 alkyl (including alkyl groups that are linear, branched, cyclic, or a combination of at least two of the foregoing), C.sub.2-C.sub.13 alkenyl, C.sub.6-C.sub.12aryl C.sub.7-C.sub.13 arylalkyl, and C.sub.7-C.sub.13 alkylaryl. The foregoing hydrocarbyl groups can, optionally, be fully or partially halogenated with fluorine, chlorine, bromine, iodine, or a combination of at least two of the foregoing. In some embodiments, including embodiments in which a transparent block polycarbonate-polysiloxane is desired, R.sup.2 is unsubstituted by halogen.
The polysiloxane blocks can each comprise 2 to 1,000 diorganosiloxane units. Within this range, the number of diorganosiloxane units can be 2 to 500, more specifically 5 to 100. In some embodiments, the number of diorganosiloxane repeat units in each block is 10 to 75, specifically 40 to 60.
In some embodiments, the polysiloxane block has the formula
##STR00009## wherein R.sup.2 is defined above; E is 2 to 1,000, specifically 2 to 500, more specifically 5 to 100, still more specifically 10 to 75, even more specifically 40 to 60; and each occurrence of Ar is independently an unsubstituted or substituted C.sub.6-C.sub.30 arylene group, wherein aromatic carbon atoms of the arylene group is directly bonded to each adjacent oxygen atom. Ar groups can be derived from a C.sub.6-C.sub.30 dihydroxyarylene compound, for example a dihydroxyarylene compound of formula
##STR00010## wherein R.sup.a, R.sup.b, R.sup.h, X.sup.a, p, and q are defined above. Examples of dihydroxyarylene compounds include hydroquinone, resorcinol, 1,1-bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane, 1,1-bis(4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxy-l-methylphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, bis(4-hydroxyphenyl sulfide), and 1,1-bis(4-hydroxy-t-butylphenyl)propane.
In some embodiments, the polysiloxane block has the formula
##STR00011## wherein R.sup.2 and E are as defined above, and each occurrence of R.sup.3 is independently (divalent) C.sub.1-C.sub.30 hydrocarbylene.
In a specific embodiment, the polysiloxane blocks have the formula
##STR00012## wherein R.sup.2 and E are as defined above; each occurrence of R.sup.4 is independently a divalent C.sub.2-C.sub.8 aliphatic group; each occurrence of M is independently halogen, cyano, nitro, C.sub.1-C.sub.8 alkyl, C.sub.1-C.sub.8 alkoxyl, C.sub.1-C.sub.8 alkylthio, C.sub.2-C.sub.8 alkenyl, C.sub.2-C.sub.8 alkenyloxyl group, C.sub.6-C.sub.10 aryl, C.sub.6-C.sub.10 aryloxyl, C.sub.7-C.sub.12 arylalkyl, C.sub.7-C.sub.12 arylalkoxyl, C.sub.7-C.sub.12 alkylaryl, or C.sub.7-C.sub.12 alkylaryloxyl; and each occurrence of v is independently 0, 1, 2, 3, or 4. In some embodiments, at least one occurrence of v is not zero, and each associated occurrence of M is independently chloro, bromo, C.sub.1-C.sub.6 alkyl (including methyl, ethyl, and n-propyl), C.sub.1-C.sub.6 alkoxyl (including methoxyl, ethoxyl, and propoxyl), or C.sub.6-C.sub.12 aryl or alkylaryl (including phenyl, chlorophenyl, and tolyl); each occurrence of R.sup.4 is independently C.sub.2-C.sub.4 alkylene (including dimethylene, trimethylene, and tetramethylene); and R.sup.2 is C.sub.1-C.sub.8 alkyl, C.sub.1-C.sub.8 haloalkyl (including 3,3,3-trifluoropropyl), C.sub.1-C.sub.8 cyanoalkyl, or C.sub.6-C.sub.12 aryl or alkylaryl (including phenyl, chlorophenyl, and tolyl). In some embodiments, each occurrence of R.sup.2 is independently methyl, 3,3,3-trifluoropropyl, or phenyl. In some embodiments, all the occurrences of R.sup.2 collective include at least one methyl and at least one 3,3,3-trifluoropropyl.
In some embodiments, the two occurrences of R.sup.2 attached to a silicon atom include at least one methyl and at least one phenyl. In some embodiments, each occurrence of v is 1, each occurrence of M is methoxyl, R.sup.4 is a divalent C.sub.1-C.sub.3 alkylene group, and each occurrence of R.sup.2 is methyl.
Blocks having the formula
##STR00013## can be derived from the corresponding dihydroxy polysiloxane having the formula
##STR00014## wherein E, v, R.sup.4, R.sup.6, and M are defined above. Such dihydroxy polysiloxanes can be prepared by a platinum-catalyzed reaction of an aliphatically unsaturated monohydric phenol with a polysiloxane hydride of the formula
##STR00015## wherein E, and R.sup.2 are defined above. Examples of aliphatically unsaturated monohydric phenols include 2-methoxy-4-allyl-phenol (eugenol), 2-allylphenol, 2-methyl-4-allylphenol, 2-allyl-4-methylphenol, 4-allyl-2-phenylphenol, 4-allyl-2-bromophenol, 4-allyl-2-t-butoxyphenol, 4-allyl-2-phenylphenol, 2-allyl-4-propylphenol, 2-allyl-4,6-dimethylphenol, 2-allyl-4-bromo-6-methylphenol, 2-allyl-6-methoxy-4-methylphenol, 2-allyl-4,6-dimethylphenol, and combinations of at least two of the foregoing.
The at least one polycarbonate block of the block polycarbonate-polysiloxane comprises carbonate units of the formula
##STR00016## wherein at least 60 percent of the total number of R.sup.1 groups are aromatic, and various specific embodiments of R.sup.1 are described above.
In some embodiments, the block polycarbonate-polysiloxane comprises, based on the weight of the block polycarbonate-polysiloxane, 70 to 97 weight percent carbonate units and 3 to 30 weight percent of diorganosiloxane units. Within this range, the block polycarbonate-polysiloxane can comprise 70 to 90 weight percent, specifically 75 to 85 weight percent, of carbonate units, and 10 to 30 weight percent, specifically 15 to 25 weight percent of diorganosiloxane units.
In some embodiments, the block polycarbonate-polysiloxane has a weight average molecular weight of 2,000 to 100,000 atomic mass units, specifically 5,000 to 50,000 atomic mass units, as determined by gel permeation chromatography using a crosslinked styrene-divinyl benzene column, a sample concentration of 1 milligram per milliliter, and bisphenol A polycarbonate standards.
In some embodiments, the block polycarbonate-polysiloxane has a melt volume flow rate, measured at 300° C. and 1.2 kilogram load according to ASTM D1238-04, of 1 to 50 cubic centimeters per 10 minutes, specifically 2 to 30 cubic centimeters per 10 minutes, more specifically 3 to 20 cubic centimeters per 10 minutes. Mixtures of block polycarbonate-polysiloxanes of different flow properties can be used to achieve desired flow properties for the composition as a whole.
In a very specific embodiment, the block polycarbonate-polysiloxane comprises, based on the weight of the block polycarbonate-polysiloxane, 10 to 30 weight percent of dimethylsiloxane units, and 70 to 90 weight percent of carbonate units of the formula
##STR00017## and the block polycarbonate-polysiloxane has a melt volume flow rate of 3 to 20 centimeter.sup.3/10 minutes measured at 300° C. and 1.2 kilogram load according to ASTM D1238-04. The carbonate units can be present in a single polycarbonate block, or distributed among multiple polycarbonate blocks. In some embodiments, the carbonate units are distributed among at least two polycarbonate blocks.
In another very specific embodiment, the block polycarbonate-polysiloxane has the formula
##STR00018## wherein x, y, and z are such that the block copolymer has 10 to 30 weight percent, specifically 15 to 25 weight percent, of polydimethylsiloxane units. In some embodiments, x is, on average, 30 to 60, specifically 30 to 56; y is on average 1 to 5, specifically 1 to 3; and z is on average 70 to 130, specifically 80 to 100. T is a divalent C.sub.3—C.sub.30 linking group, specifically a hydrocarbyl group which can be aliphatic, aromatic, or a combination of aromatic and aliphatic and can contain one or more heteroatoms including oxygen. A wide variety of linking groups and combinations thereof can be used. The T group can be derived from a eugenol or allyl end-capping agent on the polysiloxane chain. Other end-capping agents, in addition to eugenol, include aliphatically unsaturated monohydric phenols such as 2-allyl phenol and 4-allyl-2-methylphenol. The carbonate units can be present in a single polycarbonate block, or distributed among multiple polycarbonate blocks. In some embodiments, the carbonate units are distributed among at least two polycarbonate blocks.
In another very specific embodiment, the block polycarbonate-polysiloxane has the formula
##STR00019## wherein x, y, and z are such that the block copolymer has 10 to 30 weight percent, specifically 15 to 25 weight percent, of polydimethylsiloxane units. In some embodiments, x is, on average, 30 to 60, specifically 30 to 56; y is on average 1 to 5, specifically 1 to 3; and z is on average 70 to 130, specifically 80 to 100. The carbonate units can be present in a single polycarbonate block, or distributed among multiple polycarbonate blocks. In some embodiments, the carbonate units are distributed among at least two polycarbonate blocks.
The composition comprises the block polycarbonate-polysiloxane in an amount of 10 to 40 weight percent, based on the total weight of the composition. Within this range, the block polycarbonate-polysiloxane amount can be 15 to 35 weight percent, specifically 20 to 30 weight percent.
In addition to the aromatic polycarbonate and the block polycarbonate-polysiloxane, the composition comprises a poly(alkylene terephthalate). The alkylene group of the poly(alkylene terephthalate) can comprise 2 to 18 carbon atoms. Examples of alkylene groups are ethylene, 1,3-propylene, 1,4-butylene, 1,5-pentylene, 1,6-hexylene, 1,4-cyclohexylene, 1,4-cyclohexanedimethylene, and combinations thereof. In some embodiments, the alkylene group comprises ethylene, 1,4-butylene, or a combination thereof, and the poly(alkylene terephthalate comprises poly(ethylene terephthalate), poly(butylene terephthalate), or a combination thereof, respectively. In some embodiments, the alkylene group comprises 1,4-butylene and the poly(alkylene terephthalate) comprises poly(butylene terephthalate).
The poly(alkylene terephthalate) can also be a copolyester derived from terephthalic acid (or a combination of terephthalic acid and isophthalic acid) and a mixture comprising a linear C.sub.2-C.sub.6 aliphatic diol, such as ethylene glycol and/or 1,4-butylene glycol), and a C.sub.6-C.sub.12 cycloaliphatic diol, such as 1,4-cyclohexane diol, 1,4-cyclohexanedimethanol, dimethanol decalin, dimethanol bicyclooctane, 1,10-decane diol, or a combination thereof. The ester units comprising the two or more types of diols can be present in the polymer chain as individual units or as blocks of the same type of units. Specific esters of this type include poly(1,4-cyclohexylene dimethylene co-ethylene terephthalate) (PCTG) wherein greater than 50 mole percent of the ester groups are derived from 1,4-cyclohexanedimethanol; and poly(ethylene-co-1,4-cyclohexylenedimethylene terephthalate) wherein greater than 50 mole percent of the ester groups are derived from ethylene (PETG).
It will be understood that the poly(alkylene terephthalate) can include small amounts (e.g., up to 10 weight percent, specifically up to 5 weight percent) of residues of monomers other than alkylene diols and terephthalic acid. For example, the poly(alkylene terephthalate) can include the residue of isophthalic acid. As another example, the poly(alkylene terephthalate) can comprises units derived from an aliphatic acid, such as succinic acid, glutaric acid, adipic acid, pimelic acid, 1,4-cyclohexanedicarboxylic acid, and combinations thereof.
In some embodiments, the poly(alkylene terephthalate) is poly(l,4-butylene terephthalate) or “PBT” resin that is obtained by polymerizing a glycol component comprising at least 70 mole percent, specifically at least 80 mole percent, of tetramethylene glycol (1,4-butanediol), and an acid component comprising at least 70 mole percent, specifically at least 80 mole percent, terephthalic acid or polyester-forming derivatives therefore. Commercial examples of PBT include those available under the trade names VALOX™ 315 and VALOX™ 195, manufactured by SABIC Innovative Plastics.
In some embodiments, the poly(alkylene terephthalate) has an intrinsic viscosity of 0.4 to 2.0 deciliter/gram (dl/g), as measured in a 60:40 phenol/tetrachloroethane mixture at 23° C. In some embodiments, the poly(alkylene terephthalate) has an intrinsic viscosity of 0.5 to 1.5 dl/g, specifically 0.6 to 1.2 dl/g.
In some embodiments, the poly(alkylene terephthalate) has a weight average molecular weight of 10,000 to 200,000 atomic mass units, specifically 50,000 to 150,000 atomic mass units, as measured by gel permeation chromatography (GPC) using polystyrene standards. If a poly(alkylene terephthalate) having a weight average molecular weight less than 10,000 atomic mass units is used, the mechanical properties of the articles molded from the composition can be unsatisfactory. On the other hand, if a poly(alkylene terephthalate) having a weight average molecular weight greater than 200,000 atomic mass units is used, the moldability can be insufficient. The poly(alkylene terephthalate) can also comprise a mixture of two or more poly(alkylene terephthalate)s having different intrinsic viscosities and/or weight average molecular weights.
In some embodiments, the poly(alkylene terephthalate) component comprises a modified poly(butylene terephthalate), that is, a PBT derived in part from poly(ethylene terephthalate) (PET), for example recycled PET from used soft drink bottles. The PET-derived PBT polyester (referred to herein for convenience as a “modified PB%”) can be derived from a poly(ethylene terephthalate) component such as poly(ethylene terephthalate), a poly(ethylene terephthalate) copolymer, or a combination thereof. The modified PBT can further be derived from biomass-derived 1,4-butanediol, e.g., corn derived 1,4-butanediol or a 1,4-butanediol derived from a cellulosic material. Unlike conventional molding compositions containing virgin PBT (PBT that is derived from 1,4-butanediol and terephthalic acid monomers), the modified PBT contains units derived from ethylene glycol and isophthalic acid. Use of modified PBT can provide a valuable way to effectively use underutilized scrap PET (from post-consumer or post-industrial streams) in PBT thermoplastic molding compositions, thereby conserving non-renewable resources and reducing the formation of greenhouse gases, e.g., carbon dioxide.
The modified PBT can have at least one residue derived from the poly(ethylene terephthalate) component. Such residue can include residue derived from one or more of ethylene glycol groups, diethylene glycol groups, isophthalic acid groups, antimony-containing compounds, germanium-containing compounds, titanium-containing compounds, cobalt-containing compounds, tin-containing compounds, aluminum, aluminum salts, 1,3-cyclohexane dimethanol isomers, 1,4-cyclohexane dimethanol isomers, the cis isomer of 1,3-cyclohexane dimethanol, the cis isomer of 1,4-cyclohexane dimethanol, the trans isomer of 1,3-cyclohexane dimethanol, the trans isomer of 1,4-cyclohexane dimethanol, alkali salts, alkaline earth metal salts, including calcium, magnesium, sodium and potassium salts, phosphorous-containing compounds and anions, sulfur-containing compounds and anions, naphthalene dicarboxylic acids, 1,3-propanediol groups, and combinations thereof.
Depending on factors such as the type and relative amounts of poly(ethylene terephthalate) and poly(ethylene terephthalate) copolymers, the residue can include various combinations. For example, the residue can include mixtures of units derived from ethylene glycol groups and diethylene glycol groups. The residue can also include mixtures of units derived from ethylene glycol groups, diethylene glycol groups, and isophthalic acid groups. The residue derived from poly(ethylene terephthalate) can include the cis isomer of 1,3-cyclohexane dimethanol groups, the cis isomer of 1,4-cyclohexane dimethanol groups, the trans isomer of 1,3-cyclohexane dimethanol groups, the trans isomer of 1,4-cyclohexane dimethanol groups, and combinations thereof. The residue can also include a mixture of units derived from ethylene glycol groups, diethylene glycol groups, isophthalic acid groups, cis isomer of cyclohexane dimethanol groups, trans isomer of cyclohexane dimethanol groups, and combinations thereof. The residue derived from poly(ethylene terephthalate) can also include mixtures of units derived from ethylene glycol groups, diethylene glycol groups, and cobalt-containing compounds. Such cobalt-containing compound mixtures can also contain isophthalic acid groups.
The amount of the ethylene glycol groups, diethylene glycol groups, and isophthalic groups in the polymeric backbone of the modified PBT component can vary. The modified PBT ordinarily contain units derived from isophthalic acid in an amount that is at least 0.1 mole percent and can range from 0.1 to 10 mole percent. The modified PBT component can also contain units derived from ethylene glycol in an amount that is at least 0.1 mole percent and can range from 0.1 to 10 mole percent. The modified PBT component can also contain units derived from diethylene glycol in an amount of 0.1 to 10 mole percent. In some embodiments, the amount of units derived from butanediol is 95 to 99.8 mole percent. In some embodiments, the amount of units derived from terephthalic acid is 90 to 99.9 mole percent. Unless otherwise specified, all molar amounts of units derived from isophthalic acid and/or terephthalic acid are based on the total moles of units in the composition derived from diacids and/or diesters. Unless otherwise specified, all molar amounts of units derived from 1,4-butanediol, ethylene glycol, and diethylene glycol are based on the total moles of units in the composition derived from diol.
The total amount of the poly(ethylene terephthalate) component residue in the modified PBT can vary in amounts from 1.8 to 2.5 weight percent, or from 0.5 to 2 weight percent, or from 1 to 4 weight percent, based on the total weight of the modified PBT. When it is desirable to make a poly(butylene terephthalate) copolymer having a melting temperature T.sub.m that is at least 200° C., the total amount of diethylene glycol, ethylene glycol, and isophthalic acid groups should be within a certain range. As such, the total amount of the diethylene glycol, ethylene glycol, and isophthalic acid groups in the modified poly(butylene terephthalate) component can be more than 0 and less than or equal to 23 equivalents, relative to the total of 100 equivalents of diol and 100 equivalents of diacid groups in the modified PBT. The total amount of inorganic residues derived from the poly(ethylene terephthalate) can be present at more than 0 parts per million by weight (ppm) and up to 1000 ppm. Examples of such inorganic residues include antimony-containing compounds, germanium-containing compounds, titanium-containing compounds, cobalt-containing compounds, tin containing compounds, aluminum, aluminum salts, alkaline earth metal salts (including calcium and magnesium salts), alkali salts (including sodium and potassium salts), phosphorous-containing compounds and anions, sulfur-containing compounds and anions, and combinations thereof. The amounts of inorganic residues can be from 250 to 1000 ppm, more specifically from 500 to 1000 ppm.
Commercial examples of a modified PBT include those available under the trade name VALOX™ iQ Resin, manufactured by SABIC Innovative Plastics Company. The modified PBT can be derived from the poly(ethylene terephthalate) component by any method that involves depolymerization of the poly(ethylene terephthalate) component and polymerization of the depolymerized poly(ethylene terephthalate) component with 1,4-butanediol to provide the modified PBT. For example, the modified poly(butylene terephthalate) component can be made by a process that involves depolymerizing a poly(ethylene terephthalate) and/or a poly(ethylene terephthalate) copolymer, with a 1,4-butanediol component at a temperature from 180° C. to 230° C., under agitation, at a pressure that is at least atmospheric pressure in the presence of a catalyst component, at an elevated temperature, under an inert atmosphere, to produce a molten mixture containing an oligomer containing ethylene terephthalate moieties, an oligomer containing ethylene isophthalate moieties, an oligomer containing diethylene terephthalate moieties, an oligomer containing diethylene isophthalate moieties, an oligomer containing butylene terephthalate moieties, an oligomer containing butylene isophthalate moieties, a covalently bonded oligomeric moiety containing at least two of the foregoing moieties, 1,4-butanediol, ethylene glycol, or a combination thereof; and agitating the molten mixture at sub-atmospheric pressure and increasing the temperature of the molten mixture to an elevated temperature under conditions sufficient to form a modified PBT containing at least one residue derived from the poly(ethylene terephthalate) component.
The composition can comprise a combination of virgin poly(alkylene terephthalate) and modified poly(alkylene terephthalate), including a combination of virgin and modified poly(1,4-butylene terephthalate), the latter obtained from recycled poly(ethylene terephthalate) as described above.
The composition comprises the poly(alkylene terephthalate) in an amount of 5 to 35 weight percent, based on the total weight of the composition. Within this range, the poly(alkylene terephthalate) amount can be 10 to 30 weight percent, specifically 15 to 25 weight percent.
In addition to the aromatic polycarbonate, the block polycarbonate-polysiloxane, and the poly(alkylene terephthalate), the composition comprises a block polyestercarbonate. The block polyestercarbonate comprises at least one polyester block and at least one polycarbonate block. The polyester block comprises resorcinol ester repeat units having the structure
##STR00020## and the polycarbonate block comprises carbonate repeat units having the structure
##STR00021## wherein at least 60 percent of the total number of R.sup.1 groups are aromatic, and various specific embodiments of R.sup.1 are described above.
In some embodiments, the polyester block comprises resorcinol ester repeat units having the structures
##STR00022## and the polycarbonate block comprises carbonate repeat units having the structure
The composition comprises the block polyestercarbonate in an amount of 5 to 50 weight percent, based on the total weight of the composition. Within this range, the block polyestercarbonate amount can be 5 to 40 weight percent, specifically 10 to 35 weight percent, even more specifically 15 to 35 weight percent.
In addition to the aromatic polycarbonate, the block polycarbonate-polysiloxane, the poly(alkylene terephthalate), and the block polyestercarbonate, the composition comprises an organophosphate ester. Exemplary organophosphate ester flame retardants include phosphate esters comprising phenyl groups, substituted phenyl groups, or a combination of phenyl groups and substituted phenyl groups, bis-aryl phosphate esters based upon resorcinol such as, for example, resorcinol bis(diphenyl phosphate), as well as those based upon bisphenols such as, for example, bisphenol A bis(diphenyl phosphate). In some embodiments, the organophosphate ester is selected from tris(alkylphenyl) phosphates (for example, CAS Reg. No. 89492-23-9 or CAS Reg. No. 78-33-1), resorcinol bis(diphenyl phosphate) (CAS Reg. No. 57583-54-7), bisphenol A bis(diphenyl phosphate) (CAS Reg. No. 181028-79-5), triphenyl phosphate (CAS Reg. No. 115-86-6), tris(isopropylphenyl) phosphates (for example, CAS Reg. No. 68937-41-7), t-butylphenyl diphenyl phosphates (CAS Reg. No. 56803-37-3), bis(t-butylphenyl) phenyl phosphates (CAS Reg. No. 65652-41-7), tris(t-butylphenyl) phosphates (CAS Reg. No. 78-33-1), and combinations thereof.
In some embodiments the organophosphate ester comprises a bis-aryl phosphate having the formula
##STR00024## wherein R is independently at each occurrence a C.sub.1-C.sub.12 alkylene group; R.sup.9 and R.sup.10 are independently at each occurrence a C.sub.1-C.sub.5 alkyl group; R.sup.5, R.sup.6, and R.sup.7 are independently a C.sub.1-C.sub.12 hydrocarbyl group; R.sup.7 is independently at each occurrence a C.sub.1-C.sub.12 hydrocarbyl group; n is 1 to 25; and s1 and s2 are independently an integer equal to 0, 1, or 2. In some embodiments OR.sup.5, OR.sup.6, OR.sup.7 and OR.sup.8 are independently derived from phenol, a monoalkylphenol, a dialkylphenol, or a trialkylphenol.
As readily appreciated by one of ordinary skill in the art, the bis-aryl phosphate is derived from a bisphenol. Exemplary bisphenols include 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 2,2-bis(4-hydroxy-3-methylphenyl)propane, bis(4-hydroxyphenyl)methane, bis(4-hydroxy-3,5-dimethylphenyl)methane and 1,1-bis(4-hydroxyphenyl)ethane. In some embodiments, the bisphenol comprises bisphenol A. In some embodiments, the organophosphate ester comprises bisphenol A bis(diphenyl phosphate).
The composition comprises the organophosphate ester in an amount of 4 to 20 weight percent, based on the total weight of the composition. Within this range, the organophosphate ester amount can be 5 to 15 weight percent, specifically 6 to 12 weight percent, more specifically 7 to 10 weight percent.
The composition can, optionally, comprise one or more flame retardants in addition to the organophosphate ester. Such flame retardants can include metal dialkylphosphinates (such as aluminum tris(diethylphosphinate)), melamine-containing flame retardants (such as melamine phosphate, melamine pyrophosphate, melamine polyphosphate, and melamine cyanurate), metal hydroxides (such as magnesium hydroxide, aluminum hydroxide, and cobalt hydroxide), and combinations thereof. When present, such additional flame retardants can be used in an amount of 1 to 10 weight percent, based on the total weight of the composition.
The composition can, optionally, further comprise one or more additives, including flow modifiers, antioxidants, heat stabilizers, light stabilizers, ultraviolet (UV) light stabilizers, UV absorbing additives, plasticizers, lubricants, mold release agents, antistatic agents, anti-fog agents, antimicrobial agents, surface effect additives, radiation stabilizers, anti-drip agents (e.g., a styrene-acrylonitrile copolymer-encapsulated polytetrafluoroethylene (TSAN)), and combinations thereof. In general, the additives, when present, are used in a total amount of less than or equal to 5 weight percent, based on the total weight of the composition. Within this limit, the additives can be used in a total amount of less than or equal to 2 weight percent, specifically less than or equal to 1.5 weight percent.
The composition can, optionally minimize or exclude impact modifiers. Impact modifiers include, for example, natural rubber, fluoroelastomers, ethylene-propylene rubbers (EPR), ethylene-butene rubbers, ethylene-propylene-diene monomer rubbers (EPDM), acrylate rubbers, hydrogenated nitrile rubbers (HNBR), silicone elastomers, styrene-butadiene-styrene block copolymers (SBS), styrene-butadiene rubbers (SBR), styrene-(ethylene-butene)-styrene block copolymers (SEBS), styrene-isoprene-styrene block copolymers (SIS), styrene-(ethylene-propylene)-styrene block copolymers (SEPS), acrylonitrile-butadiene-styrene copolymers (ABS, including bulk ABS and high-rubber graft ABS), acrylonitrile-ethylene-propylene-diene-styrene copolymers (AES), methyl methacrylate-butadiene-styrene block copolymers (MBS), and combinations thereof. In some embodiments, the composition comprises 0 to 1 weight percent of impact modifiers. In some embodiments, the composition excludes impact modifiers.
The composition can, optionally, minimize or exclude fillers, including reinforcing fillers (such as glass fibers, talc, mica, and wollastonite), and non-reinforcing fillers (such as silica and alumina). In some embodiments, the composition comprises 0 to 1 weight percent of reinforcing fillers. In some embodiments, the composition excludes reinforcing fillers. In the context of the minimizing or excluding fillers, the metal hydroxides described above in the context of flame retardants are considered fillers.
The description continues in the full USPTO document.
About 5,086 words. The USPTO PDF has it with every drawing.
Fees are due 3.5, 7.5 and 11.5 years after grant. This patent expired on October 17, 2025, so the fee marked "not paid" was the one that went unpaid.
POLYESTER-POLYCARBONATE COMPOSITION AND ARTICLE
Filed Feb 2014 · published Aug 2015POLYESTER-POLYCARBONATE COMPOSITION AND ARTICLE
Filed Feb 2015 · published Dec 2016Polyester-polycarbonate composition and article
Filed Feb 2015 · granted Oct 2017Earlier publications, parents and continuations. None of them can still be enforced, or this patent would not be listed.
Prior art cited by the examiner or applicant. Useful when you check your own idea for novelty.
Everything on this page comes from the documents linked above.
